Electrical submersible well pumps (ESP) are often used to pump liquids from hydrocarbon producing wells. A typical ESP includes a pump driven by an electrical motor. A seal section connects between the pump and the motor to seal the drive shaft extending from the motor. The seal section may have pressure equalizing components to equalize the pressure of the lubricant in the motor with the pressure of the well fluid on the exterior. A thrust bearing module is at the lower end of the seal section for absorbing thrust imposed on the pump shaft.
The thrust bearing module has a base that connects to the upper end of the motor. The base has a bore through which the seal section shaft passes. Motor lubricant communicates through the bore in the base, through the thrust bearing assembly, and into the pressure equalizing components of the seal section. In one type of thrust bearing module, a thrust bearing retainer is located on top of the base, and the thrust bearing down thrust bearing is mounted on top of the thrust bearing retainer. A lubricant pump comprising a sleeve with a helical groove on its exterior is located in the bore in the retainer for pumping motor lubricant into the thrust bearing assembly. The motor lubricant circulates back around the outer diameter of the thrust bearing retainer to the lubricant pump.